The detection of changes in the circulation and surface topography of the optic nervehead and adjacent structures in crucial for the early diagnosis of glaucoma. A new technique, called laser contour angiography, has recently been invented (by Shapiro) to quantitate these changes and has been used to obtain high precision topographic data in normal human subjects. Because only a small proportion of ocular hypertensive patients go on to develop a visual field loss, a longitudinal study of glaucoma in human subjects would have to involve a large patient population and would require many years of observation. The recent availability of an animal model of chronic glaucoma makes it possible to study these relationships over a short time span and under well controlled conditions. Past problems with anterior chamber inflammation and corneal clouding have been solved by the use of anti-inflammatory drugs and by pharmacologic control of the intraocular pressure. We plan to continue the longitudinal study of optic disc topography and circulation in the glaucomatous eye, and also in the eyes of monkeys with experimental systemic hypertension.